Cam lock sheet clamping device



Oct. 5, 1937. e. P. REINTJES CAM LOCK SHEET CLAMPEENG DEVICE Filed April 12, 1934 g mm Z 65.

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' part of my application for patent filed July 13,

Patented Oct. 5, 1937 PATENT OFFICE 2,095,037 om LOCK sneer cmrn'mo nnvrca George P. Reinties, Kansas City, Mo.

Application April 12, 1934, Serial No. 720,235

5 Claims. (01. sa-so This invention constitutes a continuation in 1931, Serial No. 550,347, and relates to sheet clamping devices and is particularly adapted for use in clamping plates or sheets to a skeleton frame for the production of tanks, grain bins and the like, and is moreoveralso suitable for securing the outside sheathing of furnaces or boilers where the sheathing is subjected to expansion and contraction due to the heat of the furnace orthe' like. It has heretofore been standard practicein furnace and other skeleton metal constructions to secure the pressed or molded asbestos or metal sheets by bolting themto the upright skeleton frame through the matching of punched holes. This method requires lay-out drawings and the like, and is expensive, slow and on the whole, unsatisfactory.

The general object of the present invention therefore, is to provide a clamping mechanismof strong, durable, eflicient and inexpensive construction, whereby plates or sheets may be readily applied to and securely held in position without the necessity of punching the edges to match up with openings in the supporting framework. Another object of the invention is to provide a clamping mechanism of the general character outlined which is particularly adapted'to accommodate expansion and contraction of the sheathing material of a furnace or the like.

A further object .of the invention is to produce a clamping structure in 'which the cam clamps are provided with a plurality of operating faces f for progressively increasing the clamping pressure, each successive clamping face being in effect the chord of a larger circle, whereby the cam is automatically locked with any of its faces in operative position.

With the general objects named in view, and other as will hereinafter appear, the invention consists in certain novel and useful features of construction and organization of parts as hereinafter described and claimed; and in order that it may be fully understood, reference is to be had to the accompanying drawing, in which:-

Flgure 1 is a perspective view of a skeleton framework or the like, embodying the invention, partly broken away to more clearly illustrate the parts.

Figure 2 is a section through a clamp mechanism embodying the invention.

Figure 3 is a section on the line IIIIII Figure 2.

Figure 4 is a section, similar to Figure 2, but of a modified type of cam clamp.

drical shaft portion I.

Figure 5 is a section on the line V-V of Figure 4.

In the said drawing, where like reference characters identify corresponding parts in all of the figures, I represents an upright skeleton framework around or supporting a tank, furnace or the like. Bridging the space between the columns I, and secured thereto, are horizontal angle iron base members or supports 2, which, between the same columns, will be vertically spaced apart and thus produce a strong skeleton structure providing relatively rectangular openings to be covered or spanned by and carry plates or sheets,

hereinafter identified, to be clamped in position. Where the columns are widely spaced apart, vertical base members may be interposed between them as shown, such members being adapted for connection at their ends with adjacent horizontal base members as indicated at In. The base members 2 and 2a are provided with flanges l and 3a projecting at right angles to their respective base portions, and the latter are shown as of T shape, but this shape is necessary or desirable only where plates are to be clamped in place at both sides of the flanges. L shaped base members are suitable and preferable at the ends and top and bottom of the furnace, tank or other structure. In some cases flanges 3 may be formed on or secured directly to the vertical columns I.

The flanges of the base members for the type of clamping mechanism shown in Figures 1, 2 and 3, are formed with a plurality of elongated spaced holes oropenings 4, and journaled in each of said openings is a clampingmechanism comprising a pair of cams 5 and 6, each cam having a plurality of clamping faces so that sheets of different gage may be mounted in clamped pofltion. As illustrated, each cam has a pair of clamping faces 5a and 6a in the figures mentioned, respectively spaced closer to and further from the axis of rotation, and said cams are connected together by an intermediate cylin- Each cam 6 is oblong and of size to pass through its respective opening 4, while the cams I have circular flanges of such diameter that they cannot pass through the openings. Hence, where the devices are assembled on a horizontal flange with cams 5 uppermost, they cannot slip from position, even when loose. In order that the cams may be rotated to clamping position, one end of each is formed with any suitable head to receive a wrench or other tool.

Each face a and to of each cam is formed with a notched portion 0 of such width as to embrace a clamping rod II or the like, interposed between the cam and the adjacent face of the plate P, it being noted that the operative faces of thejceme as shown at II, are so made that when the cam is infull clamping position, it has,

in eil'ect, passed center so thatit is self-locking.

,than.illustretedinPlgures2end3,and-inwhich the cam members are'identical at opposite ends ofthedevloeinsteedofbeingofdissimilershape' as in theprevious flgures of the drawins. In this 7 modiiioetiome cylindrical clamping lug or'cam" l4 isformed etitsopposite ends with wrench ensuin heedsll, endhes one of its sides flattened as at. Adjecent'the headsthe camis formed'with scores or groom II which spirally approechthe exis'of the clamping ing or cam is. The bottom of each spiral groove is formed with a series offlet it (see Figure 5), end as the groove is struck on a spiral the result is-that theclam'ping are each, in eflect, the chord of a smaller circle, counting from'the perimeter of the clamp lug. Thus the .sboulder or corner II between each pair of adjacent clamping'surfe'ces iorms a locking means, so that-the cam-cannot accidentally loosen up afterinstallatiomasthetighteningofthe cam requiresthat'itbeturned pestcenter asfar'asits.

corner is concerned. since the cornerv is on the perimeter of a circle, whllethe face of the vcam is a chord of such circle. The construction of the cam lugis clearly apparent'from a consideration of Figureb, on which the parts appear as in actual practice. From a consideration of the construction, it will be apparent that the cam surfaces may be' protruding rather than receding for cooperative engagement with the face of a plate or the like, to be clamped in position. In this construction, the cam device, i fltted in a circular hole in the hase rather than in an oblong hole, as'in Figures 2 and 3, and the lug is provided with a protruding shoulder at one end to keep it from ialling from position when assembled on a horizontal base member.

Inthe preferred constructions it will be noted that the faces of the base members in both types, converge toward their respective flanges asin standard T, or I beams, so that initially, or before suflicient clamping action occurs (see Figure- 3), the extreme marginal edges of the plates only are in contact with said base faces, and that clamping Pressure may springthe plates. In

some cases it may be desirable to supply packing as illustrated to make a jointliquid and air tight. In Figure 4,-th e plates appear in their sprung positions as shown by the slight bending of their marginal portions engaged by elements it.

From the above description, it will be apparent that I have described and illustrated a construction embodying the features of advantage set forth as desirable, and it is to be understood that I reserve the right to make all changeswithout within the spirit the ambit of the prior art and of the invention.

. Icleimzl. A sheet fastening, construction comprising a base member having a projecting flange, said base member being adapted to extend parallel to sheets received on opposite sides of its flange,v

clamping members in contact with the faces of each sheet in opposition to the base member,

and cam clamping mechanism journaled in the flange and arranged in spaced relation and adapted to simultaneously apply clamping pressure to seidclamping members.

2. 'A sheet fastening construction comprising a I plurality of spaced upright columns, a base member secured to and bridging the space between said columns and having a projecting flange, said base member being adapted to extend parallel to sheets received on oppositesld'es of its flange, clamping members in contact with the faces oi each sheet in opposition to the base member,

and cam clamping mechanisms carried by and joumaled on the flange and in spaced relation and adapted to'simultaneously apply clamping pressure on both of the clamping members.

3. A cam clamp for sheets, comprising a shaft formed adjacent its ends. with cam members. one

of said cam members being larger and theother smaller than an opening adapted. to form a journal for the portion of the shaft intermediate the cam members.

' 4. A sheet fastening construction, comprising a base member having a flange outstanding from its face, the said face at opposite sides of said flange, converging-toward the latter to stand at slight angles relative to theplane of sheets received on opposite sides of said flange and initially engaging at their extreme margins with said sloping faces, spaced clamping devices mounted on said flanges at opposite sides of the sheets fromthe base ,member, and clamping elements interposed between the clamping devices and said sheets for springing the marginal portions of the latter to conform to and flt flatly against the sloping faces of the base member.

I 5. The combination with a base member having a flange outstanding from itsface provided with v a line of openings, in integrally formed clamping device for each opening, each device having an intermediate portion rotatably cuss-s ns one GEORGE P. 

